14.1.4(2)单项式与多项式相乘一、选择题1.化简2(21)(2)xxxx的结果是()A.3xxB.3xxC.21xD.31x2.化简()()()abcbcacab的结果是()A.222abbcacB.22abbcC.2abD.2bc3.如图14-2是L形钢条截面,它的面积为()A.ac+bcB.ac+(b-c)cC.(a-c)c+(b-c)cD.a+b+2c+(a-c)+(b-c)4.下列各式中计算错误的是()A.3422(231)462xxxxxxB.232(1)bbbbbbC.231(22)2xxxxD.342232(31)2323xxxxxx5.2211(6)(6)23abababab的结果为()A.2236abB.3222536ababC.2332223236abababD.232236abab二、填空题1.22(3)(21)xxx。2.321(248)()2xxx。3.222(1)3(1)abababab。4.2232(3)(23)3(25)xxxxxx。5.228(34)(3)mmmmm。6.7(21)3(41)2(3)1xxxxxx。7.22223(2)()abababa。8.223263()(2)2(1)xxyxxy。9.当t=1时,代数式322[23(22)]ttttt的值为。10.若20xy,则代数式3342()xxyxyy的值为。三、解答题1.计算下列各题(1)111()()(2)326aababab(2)32222211(2)(2)()342xyxyxyxyxyz(3)223121(3)()232xyyxy(4)3212[2()]43abaabb(5)32325431()(2)4(75)2aabababab2.已知26ab,求253()abababb的值。3.若12x,1y,求2222()()3()xxxyyyxxyyxyyx的值。4.已知:20ab,求证:332()40aababb。四、探索题:1.先化简,再求值:22(69)(815)2(3)xxxxxxxx,其中16x。2.已知225(2520)0mmn,求2(2)2(52)3(65)3(45)mmnmnmnnmn的值。3.解方程:2(25)(2)6xxxxx.4.已知:单项式M、N满足222(3)6xMxxyN,求M、N。